The invention relates to a method of severing a plate of brittle material, in which a thermal load is provided along a heating track on at least one major surface of a plate to be severed, which has in a side a crack initiation as initiation for a crack, as a result of which stresses are produced in the plate, which, starting from the crack initiation, cause a crack square with the surface along a desired cutting line.
A method of the kind to which the present invention relates is known from DE 28,13,302 C2. In this known method, a crack initiation is provided in a side of a flat glass plate, the plate is heated in one of two consecutively arranged regions symmetrical with respect to the desired cutting line and is cooled in the other of these regions. A a result of which, due to temperature gradients, thermal stresses are produced in the plate, which cause a crack, starting from the crack initiation. When the plate is severed symmetrically, the crack follows the desired cutting line. However, when the plate is severed asymmetrically, the crack deviates from the desired cutting line.